Display device

ABSTRACT

A display device is provided, which includes a first substrate, a first display structure, a second display structure, a first optical film, a second optical film, a first adhesive layer and a second adhesive layer. The first and second display structures are disposed on the first substrate. The first display structure is disposed between the first substrate and the first optical film. The second display structure is disposed between the first substrate and the second optical film. The first and second optical films are separated. The first adhesive layer is disposed between the first display structure and first optical film. The second adhesive layer is disposed between the second display structure and second optical film. The first and second display structures are different from each other and are selected from a liquid-crystal display, an organic light-emitting diode display, an inorganic light-emitting diode display or a laser display.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of pending U.S. patent applicationSer. No. 15/972,439, filed May 7, 2018, the entirety of which isincorporated by reference herein.

BACKGROUND Technical Field

The present disclosure relates to a display device. The disclosure inparticular relates to a hybrid display device.

Description of the Related Art

Electronic products that come with a display panel, such as smartphones,tablets, notebooks, monitors, and TVs, have become indispensablenecessities in modern life. With the flourishing development of suchportable electronic products, consumers have higher expectationsregarding quality, functionality, and price. The development ofnext-generation display devices has been focused on techniques that areenergy-saving and environmentally friendly.

Different types of light-emitting structures have different performancecharacteristics that are more or less useful in different circumstancesor when used in different ways. Hybrid display devices combiningdifferent types of light-emitting structures have recently beendeveloped. Hybrid display devices may possess multiple characteristics,advantages, or functions because they have different types oflight-emitting structures.

However, the mechanism that emits light and the configuration of thelight sources can vary in the different types of light-emittingstructures. Heterogeneities in light intensity or resolution may bepresent between different types of light-emitting structures, especiallyat the boundaries where different types of light-emitting structures areintegrated. As such, the visual quality may be not uniform in the hybriddisplay device.

Accordingly, it is desirable to develop a design that can effectivelyreduce heterogeneity in the hybrid display device.

SUMMARY

In accordance with some embodiments of the present disclosure, a displaydevice is provided. The display device includes a first substrate, afirst display structure, a second display structure, a first opticalfilm, a second optical film, a first adhesive layer and a secondadhesive layer. The first display structure is disposed on the firstsubstrate. The second display structure is disposed on the firstsubstrate. The first display structure is disposed between the firstsubstrate and the first optical film. The second display structure isdisposed between the first substrate and the second optical film. Thefirst optical film and the second optical film are separated. The firstadhesive layer is disposed between the first display structure and firstoptical film. The second adhesive layer is disposed between the seconddisplay structure and second optical film. The first display structureand the second display structure are different from each other and areselected from a group consisting of: a liquid-crystal display; anorganic light-emitting diode display; an inorganic light-emitting diodedisplay; and a laser display; and wherein the first polarizing structureis disposed on the first display structure and the second displaystructure.

A detailed description is given in the following embodiments withreference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure may be more fully understood by reading the subsequentdetailed description and examples with references made to theaccompanying drawings, wherein:

FIG. 1 illustrates a cross-sectional view of a display device inaccordance with some embodiments of the present disclosure.

FIG. 2 illustrates a cross-sectional view of a display device inaccordance with some embodiments of the present disclosure.

FIG. 3 illustrates a cross-sectional view of a display device inaccordance with some embodiments of the present disclosure.

FIG. 4 illustrates a cross-sectional view of a display device inaccordance with some other embodiments of the present disclosure.

FIGS. 5A-5E illustrate the cross-sectional views of the display deviceduring the manufacturing process in accordance with some embodiments ofthe present disclosure.

FIGS. 6A-6C illustrate the cross-sectional views of the display devicein accordance with some embodiments of the present disclosure.

FIG. 7A illustrates a cross-sectional view of a display device inaccordance with some embodiments of the present disclosure.

FIG. 7B illustrates a diagram of the display device in a folded form.

FIGS. 8A-8B illustrate the cross-sectional views of the display devicein accordance with some embodiments of the present disclosure.

FIG. 9 illustrates a cross-sectional view of a display device inaccordance with some embodiments of the present disclosure.

FIG. 10 illustrates a cross-sectional view of a display device inaccordance with some other embodiments of the present disclosure.

FIG. 11 illustrates a cross-sectional view of a display device inaccordance with some other embodiments of the present disclosure.

FIG. 12 illustrates a cross-sectional view of a display device inaccordance with some other embodiments of the present disclosure.

FIG. 13 illustrates a cross-sectional view of a display device inaccordance with some embodiments of the present disclosure.

FIGS. 14A-14B illustrate the cross-sectional views of the display devicein accordance with some embodiments of the present disclosure.

FIG. 15 illustrates a diagram showing the pixels of the display units ina display device in accordance with some embodiments of the presentdisclosure.

FIG. 16 illustrates a diagram showing the assembly of the display unitsin accordance with some embodiments of the present disclosure.

DETAILED DESCRIPTION

The display device of the present disclosure and the manufacturingmethod thereof are described in detail in the following description. Inthe following detailed description, for purposes of explanation,numerous specific details and embodiments are set forth in order toprovide a thorough understanding of the present disclosure. The specificelements and configurations described in the following detaileddescription are set forth in order to clearly describe the presentdisclosure. It will be apparent, however, that the exemplary embodimentsset forth herein are used merely for the purpose of illustration, andthe inventive concept may be embodied in various forms without beinglimited to those exemplary embodiments. In addition, the drawings ofdifferent embodiments may use like and/or corresponding numerals todenote like and/or corresponding elements in order to clearly describethe present disclosure. However, the use of like and/or correspondingnumerals in the drawings of different embodiments does not suggest anycorrelation between different embodiments. In addition, in thisspecification, expressions such as “first material layer disposedon/over a second material layer”, may indicate the direct contact of thefirst material layer and the second material layer, or it may indicate anon-contact state with one or more intermediate layers between the firstmaterial layer and the second material layer. In the above situation,the first material layer may not be in direct contact with the secondmaterial layer.

It should be noted that the elements or devices in the drawings of thepresent disclosure may be present in any form or configuration known tothose with ordinary skill in the art. In addition, the expressions “alayer overlying another layer”, “a layer is disposed above anotherlayer”, “a layer is disposed on another layer” and “a layer is disposedover another layer” may indicate that the layer is in direct contactwith the other layer, or that the layer is not in direct contact withthe other layer, there being one or more intermediate layers disposedbetween the layer and the other layer.

In addition, in this specification, relative expressions are used. Forexample, “lower”, “bottom”, “higher” or “top” are used to describe theposition of one element relative to another. It should be appreciatedthat if a device is flipped upside down, an element that is “lower” willbecome an element that is “higher”.

It should be understood that, although the terms first, second, thirdetc. may be used herein to describe various elements, components,regions, layers, portions and/or sections, these elements, components,regions, layers, portions and/or sections should not be limited by theseterms. These terms are only used to distinguish one element, component,region, layer, portion or section from another region, layer or section.Thus, a first element, component, region, layer, portion or sectiondiscussed below could be termed a second element, component, region,layer, portion or section without departing from the teachings of thepresent disclosure.

It should be understood that this description of the exemplaryembodiments is intended to be read in connection with the accompanyingdrawings, which are to be considered part of the entire writtendescription. The drawings are not drawn to scale. In addition,structures and devices are shown schematically in order to simplify thedrawing.

The terms “about” and “substantially” typically mean +/−20% of thestated value, more typically +/−10% of the stated value, more typically+/−5% of the stated value, more typically +/−3% of the stated value,more typically +/−2% of the stated value, more typically +/−1% of thestated value and even more typically +/−0.5% of the stated value. Thestated value of the present disclosure is an approximate value. Whenthere is no specific description, the stated value includes the meaningof “about” or “substantially”.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this disclosure belongs. It should be appreciated that,in each case, the term, which is defined in a commonly used dictionary,should be interpreted as having a meaning that conforms to the relativeskills of the present disclosure and the background or the context ofthe present disclosure, and should not be interpreted in an idealized oroverly formal manner unless so defined.

In addition, in some embodiments of the present disclosure, termsconcerning attachments, coupling and the like, such as “connected” and“interconnected,” refer to a relationship wherein structures are securedor attached to one another either directly or indirectly throughintervening structures, as well as both movable or rigid attachments orrelationships, unless expressly described otherwise.

FIG. 1 illustrates a cross-sectional view of a display device 10 inaccordance with some embodiments of the present disclosure. It should beunderstood that additional features may be added to the display devicein some embodiments of the present disclosure. In some other embodimentsof the present disclosure, some of the features described below may bereplaced or eliminated.

Referring to FIG. 1 , the display device 10 may include a firstsubstrate 102, a first display structure 104 and a second displaystructure 106. The first substrate 102 includes a first region R1 and asecond region R2. The first display structure 104 is disposed on thefirst region R1 of the first substrate 102, and the second displaystructure 106 is disposed on the second region R2 of the first substrate102. The first display device 104 is disposed adjacent to the seconddisplay structure 106. In some embodiment, the first display device 104is in contact with the second display structure 106. The first displaystructure 104 and the second display structure 106 are each selectedfrom a group consisting of a liquid-crystal display, an organiclight-emitting diode display, an inorganic light-emitting diode displayand a laser display. However, the first display structure 104 isdifferent from the second display structure 106. In some embodiments,the resolution of the first display structure 104 is different from theresolution of the second display structure 106. In some embodiments, theresolution of the first display structure 104 is the same as theresolution of the second display structure 106.

For example, as shown in FIG. 1 , the first display structure 104 can bea liquid-crystal display and the second display structure 106 can be aninorganic light-emitting diode display. The inorganic light-emittingdiode display can be mini LED display or micro LED display in accordancewith some embodiments of the present disclosure. For example, thecross-sectional area of the micro LED may have a length of about 1 μm toabout 150 μm and may have a width ranging from about 1 μm to about 150μm. In some embodiments, the micro LED may have a size ranging fromabout 1 μm×1 μm×1 μm to about 150 μm×150 μm×150 μm.

Specifically, in this embodiment, the first display structure 104 (aliquid-crystal display) includes a second substrate 114 disposedopposite to the first substrate 102. The first substrate 102 has a firstside 102 a and a second side 102 b, and the second substrate 114 has afirst side 114 a and a second side 114 b. The second substrate 114 isdisposed on the first side 102 a of the first substrate 102, such thatthe first side 102 a of the first substrate 102 and the second side 114b of the second substrate 114 face to each other. A first driving layer108 is disposed on the first side 102 a of the first substrate 102, acolor filter layer 112 is disposed on the second side 114 b of thesecond substrate 114, and a liquid crystal layer 110 is disposed betweenthe first driving layer 108 and the color filter layer 112.

The first driving layer 108 may serve as a switch for the first displaystructure 104. In some embodiments, the first driving layer 108 mayinclude an active driving circuit including thin-film transistors (TFT)or a passive driving circuit. In some other embodiments, the firstdriving layer 108 may be controlled by an IC or a microchip. Theliquid-crystal layer 110 is formed of liquid-crystal molecules. Thecolor filter layer 112 may include, but is not limited to, red lightfilter, green light filter and blue light filter. In addition, thematerials of the first substrate 102 and the second substrate 114 mayinclude, but are not limited to, glass, quartz, sapphire, silicon wafer,polycarbonate (PC), polyimide (PI), polyethylene terephthalate (PET),liquid-crystal polymers (LCP), rubbers, glass fibers, ceramics, otherpolymer materials, any other suitable substrate material, or acombination thereof. The first substrate 102 and the second substrate114 may be a flexible substrate in accordance with some embodiments.Moreover, the first substrate 102 and the second substrate 114 may betransparent or semi-transparent so as not to significantly degrade thelight extraction efficiency of the backlight unit 118 in accordance withsome embodiments where a backlight source is present. In someembodiments, the material of the first substrate 102 is the same as thatof the second substrate 114. In some embodiments, the material of thefirst substrate 102 is different from that of the second substrate 114.

Still referring to FIG. 1 , the display device 10 further includes afirst polarizing structure 130 disposed on the first side 102 a of thefirst substrate 102. Specifically, the first polarizing structure 130 isdisposed on the first display structure 104 and the second displaystructure 106. In some embodiments, the first polarizing structure 130can be a continuous layer, as shown in FIG. 1 . Alternatively, in otherembodiments, the first polarizing structure 130 can include two separatelayers. For example, as shown in FIG. 9 , the first polarizing structure930 includes a polarizing layer 931 disposed on the first displaystructure 104 and a polarizing layer 932 disposed on the second displaystructure 106. In addition, a second polarizing structure 116 may befurther disposed on the second side 102 b of the first substrate 102.Similarly, the second polarizing structure 116 can be a continuous layeror two separate layers in the first region R1 and the second region R2.In addition, a backlight unit 118 can be disposed on the second side 102b of the first substrate 102 and below the second polarizing structure116, to provide light source to the first display structure 104 in thefirst region R1.

The material of the first polarizing structure 130 and the secondpolarizing structure 116 can include, but are not limited to, poly vinylalcohol (PVA), any other suitable materials or a combination thereof.For example, the first polarizing structure 130 and the secondpolarizing structure 116 can include a PVA film with a triacetylcellulose (TAC) film serving as a protective layer in accordance withsome embodiments. In some embodiments, the first polarizing structure130 and the second polarizing structure 116 can include a metalpatterned layer such as a wire grid polarizer (WGP). The backlight unit118 may include, but is not limited to, a light-emitting diode, a microlight-emitting diode, electroluminescence, any other suitablelight-emitting element, or a combination thereof. The materials of thebacklight unit 118 may include, but are not limited to, quantum dot (QD)materials, fluorescence materials, phosphor materials, any othersuitable light-emitting materials, or a combination thereof. In someembodiments, the backlight unit 118 may emit white light, green light,blue light, yellow light, a light of any other suitable color, or alight of any other suitable wavelength, but it is not limited thereto.In this embodiment, the backlight unit 118 may emit white light.

Still referring to FIG. 1 , on the other hand, the second displaystructure 106 (for example, an inorganic light-emitting diode display)may include a second driving layer 120, a first light-emitting layer 122disposed on and electrically connected to the second driving layer 120,and a first encapsulation layer 124 disposed on the first light-emittinglayer 122. In other words, the first light-emitting layer 122 isencapsulated by the first encapsulation layer 124, which may preventmoisture or oxygen from damaging the first light-emitting layer 122.

In some embodiments, the second driving layer 120 may be a printedcircuit board (PCB). In some embodiments, the second driving layer 120may include an active driving circuit including thin-film transistors(TFT) or a passive driving circuit. In some other embodiments, thesecond driving layer 120 may be controlled by an IC or a microchip. Thefirst light-emitting layer 122 may include the pixels of thelight-emitting diode, the pixels of the micro light-emitting diode, or acombination thereof. In some embodiments, the first light-emitting layer122 may include, but is not limited to, the subpixels for emitting redlight, green light and blue light.

In some embodiments, the first encapsulation layer 124 may betransparent or semi-transparent so as not to significantly degrade thelight extraction efficiency of the first light-emitting layer 122. Thefirst encapsulation layer 124 may be formed of organic material,inorganic material, or combinations thereof. In some embodiments, theinorganic material may include, but is not limited to, silicon nitride,silicon oxide, silicon oxynitride, aluminum oxide, any other suitableencapsulation materials, or a combination thereof. In some embodiments,the organic material may include, but is not limited to, epoxy resins,acrylic resins such as polymethylmetacrylate (PMMA), benzocyclobutene(BCB), polyimide, and polyester, polydimethylsiloxane (PDMS),polyfluoroalkoxy (PFA), epoxy, any other suitable protective materials,or a combination thereof. In some embodiments, the first encapsulationlayer 124 may be formed by using chemical vapor deposition (CVD),spin-on coating, printing or a combination thereof.

As shown in FIG. 1 , the top surface 124 a of the first encapsulationlayer 124 may be not level with the surface of the first side 114 a ofthe second substrate 114 in accordance with some embodiments. Aprotecting layer 126 can be further disposed on the first displaystructure 104 and the second display structure 106 to obtain asubstantially flat or planar surface, on which an optical film can beformed easily. For example, the first polarizing structure 130 can beadhered to the protecting layer 126 by a first adhesive layer 132.Specifically, the protecting layer 126 may be disposed on the first side114 a of the second substrate 114 of the first display structure 104 andon the first encapsulation layer 124 of the second display structure106. The first polarizing structure 130 can be a continuous layer andextend on both the first display structure 104 and the second displaystructure 106. A portion of the protecting layer 126 that is disposed onthe first display structure 104 (in the first region R1) has a firstthickness T₁ and another portion of the protecting layer 126 that isdisposed on the second display structure 106 (in the second region R2)has a second thickness T₂. In some embodiments, the first thickness T₁is not equal to the second thickness T₂. In other words, a portion ofthe protecting layer 126 that is disposed on the first display structure104 and another portion of the protecting layer 126 that is disposed onthe second display structure 106 are different in thickness. In someembodiments, the first thickness T₁ can be smaller than the secondthickness T₂. As described above, the top surface 126 a of theprotecting layer 126 is substantially planarized in accordance with someembodiments. The protecting layer 126 may serve as a planarizationlayer.

In some embodiments, the protecting layer 126 may be transparent orsemi-transparent so that the light extraction efficiency of the firstdisplay structure 104 and the second display structure 106 may be lessaffected. The protecting layer 126 may be formed of organic materials,inorganic materials, or combinations thereof. In some embodiments, theinorganic material may include, but is not limited to, silicon nitride,silicon oxide, silicon oxynitride, aluminum oxide, any other suitableencapsulation materials, or a combination thereof. In some embodiments,the organic material may include, but is not limited to, epoxy resins,acrylic resins such as polymethylmetacrylate (PMMA), benzocyclobutene(BCB), polyimide, and polyester, polydimethylsiloxane (PDMS),polyfluoroalkoxy (PFA), any other suitable protective materials, or acombination thereof. In some embodiments, the protecting layer 126 maybe formed by using chemical vapor deposition (CVD), spin-on coating,printing or a combination thereof.

In addition, the display device 10 may further include a sealing portion128 disposed adjacent to the liquid-crystal layer 110. The sealingportion 128 can be disposed on the first side 102 a of the firstsubstrate 102 in the second region R2, and can prevent theliquid-crystal molecule of the liquid-crystal layer 110 from leakage.The sealing portion 128 can at least partially overlap the secondsubstrate 114 in accordance with some embodiments. In other words, atleast a portion of the sealing portion 128 is disposed between the firstsubstrate 102 and the second substrate 114, which is labeled as 128A inFIG. 1 . The sealing portion 128 may be in contact with theliquid-crystal layer 110, the color filter layer 112 of the firstdisplay structure 104, and the second driving layer 120 of the seconddisplay structure 106.

The sealing portion 128 may include, but is not limited to, sealantglue. The sealing portion 128 may be formed of a single material or thecomposite layers of the following materials. For example, the materialof the sealing portion 128 may include, but is not limited to,polyethylene terephthalate (PET), polyethylene (PE), polyethersulfone(PES), polycarbonate (PC), polymethylmethacrylate (PMMA), epoxy orglass. In some embodiments, the sealing portion 128 may be aphoto-curing sealant (UV light or general visible light), a thermalcuring sealant, or a photothermal curing sealant. In addition, in someembodiments, the sealing portion 128 may be formed by coating, spraying,screen printing, any other suitable methods, or a combination thereof,but it is not limited thereto.

In addition, the display device 10 may further include a panel drivingportion 134 to control or process the signals of the first driving layer108 of the first display structure 104 and the second driving layer 120of the second display structure 106 via separate routes (not shown). Thepanel driving portion 134 may provide signals to control the switchingon or off of the display structures. The panel driving portion 134 mayinclude the signal circuits and the driving circuits for controlling thepanel. In some embodiments, the panel driving portion 134 can be aprinted circuit board (PCB) or a chip on film (COF) structure. The paneldriving portion 134 may include an active driving circuit or a passivedriving circuit. In some embodiments, the panel driving portion 134 maybe controlled by an IC or a microchip. The panel driving portion 134 canbe disposed on a position corresponding to the second region R2, asshown in FIG. 1 , and can also be disposed on a position correspondingto the first region R1, or corresponding to both the first region R1 andthe second region R2.

Next, referring to FIG. 2 , FIG. 2 illustrates a cross-sectional view ofa display device 20 in accordance with some embodiments of the presentdisclosure. It should be understood that the same or similar elements orlayers in above and below contexts are represented by the same orsimilar reference numerals. The materials, manufacturing methods andfunctions of these elements or layers are the same or similar to thosedescribed above, and thus will not be repeated herein. FIG. 2 differsfrom FIG. 1 in that the first display structure 104 is replaced by anorganic light-emitting diode display. The second display structure 106is an inorganic light-emitting diode display, which is similar to thesecond display structure in FIG. 1 .

As shown in FIG. 2 , the first display device 104 includes a secondlight-emitting layer 136 disposed on the first driving layer 108 and asecond encapsulation layer 138 disposed on the second light-emittinglayer 136. The second encapsulation layer 138 is disposed between theprotecting layer 126 and the second light-emitting layer 136 toencapsulate the second light-emitting layer 136. The secondencapsulation layer 138 may prevent moisture or oxygen from damaging thesecond light-emitting layer 136. In some embodiments, the secondencapsulation layer 138 may be in contact with the first encapsulationlayer 124 of the second display structure 106.

The second light-emitting layer 136 may include the pixels of the OLED.In some embodiments, the light-emitting layer 136 may include, but isnot limited to, the subpixels for emitting red light, green light andblue light. In some embodiments, the second encapsulation layer 138 maybe transparent or semi-transparent so as not to significantly degradethe light extraction efficiency of the second light-emitting layer 136.The second encapsulation layer 138 can be formed of material similar tothat of the first encapsulation layer 124 as mentioned above, and thusis not repeated herein.

As shown in FIG. 2 , in some embodiments, the second encapsulation layer138 can extend from the first region R1 to the second region R2. Inother embodiments, the second encapsulation layer 138 can be disposedonly in the first region R1, but not in the second region R2. After thefirst encapsulation layer 124 and the second encapsulation layer 138 areformed, the top surface 124 a of the first encapsulation layer 124 maybe not level with the top surface 138 a of the second encapsulationlayer 138 in accordance with some embodiments. A protecting layer 126can be further disposed on the second encapsulation layer 138 in thefirst region R1 and the first encapsulation layer 124 in the secondregion R2 to obtain a substantially flat or planar surface, on which anoptical film can be formed easily. For example, a retardation layer 140can be disposed on the top surface 126 a of the protecting layer 126.Moreover, the first polarizing structure 130 can be adhered to theretardation layer 140 by a first adhesive layer 132. In this embodiment,a portion of the protecting layer 126 that is disposed on the firstdisplay structure 104 has a third thickness T₃ and another portion ofthe protecting layer 126 that is disposed on the second displaystructure 106 has a fourth thickness T₄. In some embodiments, the thirdthickness T₃ is not equal to the fourth thickness T₄. In someembodiments, the third thickness T₃ is greater than the fourth thicknessT₄. As described above, the top surface 126 a of the protecting layer126 is substantially planarized in accordance with some embodiments.

In addition, the retardation layer 140 may possess anti-reflectivecharacteristics. In some embodiments, the retardation layer 140 may be acircular polarizer (¼ wave retarder). In particular, the combination ofthe retardation layer 140 and the first polarizing structure 130 mayprovide anti-reflection effect for the display device 20.

The retardation layer 140 may be formed of composite materials havingbirefringence characteristics. In some embodiments, the material of theretardation layer 140 may include, but is not limited to, triacetylcellulose (TAC), N-triacetyl cellulose (N-TAC), cyclic olefin polymer(COP), polyimide (PI), any other suitable protective materials,metamaterials, dielectrics, metal meshes, or a combination thereof. Insome embodiments, the retardation layer 140 may have a multilayerstructure. In some embodiments, the retardation layer 140 may be formedby using chemical vapor deposition (CVD), spin-on coating, printing,evaporation, sputtering, any other suitable methods or a combinationthereof. In some embodiments, a ready-made retardation layer may bedirectly disposed on the protecting layer 126 using a suitable adhesive.

Next, referring to FIG. 3 , FIG. 3 illustrates a cross-sectional view ofa display device 30 in accordance with some embodiments of the presentdisclosure. In the embodiment shown in FIG. 3 , the first displaystructure 104 is a liquid-crystal display and the second displaystructure 106 is an organic light-emitting diode display. The differencebetween the embodiments shown in FIG. 3 and FIG. 1 is that the seconddisplay structure 106 is an organic light-emitting diode display in FIG.3 . Similarly, the display device 30 includes the sealing portion 128disposed adjacent to the liquid-crystal layer 110. The sealing portion128 at least partially overlaps the second substrate 114 in accordancewith some embodiments.

In addition, in accordance with some embodiments of the presentdisclosure, the display device may include a retardation layer 140disposed on the region where the organic light-emitting diode display,the inorganic light-emitting diode display, or the laser display isdisposed. For example, FIG. 4 illustrates a cross-sectional view of adisplay device 40 in accordance with some other embodiments of thepresent disclosure. FIG. 4 differs from FIG. 1 in that a retardationlayer 140 is disposed in the second region R2 corresponding to where thesecond display structure 106 (the inorganic light-emitting diodedisplay) is located. Furthermore, the retardation layer 140 may bedisposed at any position above the organic light-emitting diode display,the inorganic light-emitting diode display or the laser display. Forexample, the retardation layer 140 may be disposed between theprotecting layer 126 and the first adhesive layer 132 (as shown in FIG.2 ) in accordance with some embodiments. In some other embodiments, theretardation layer 140 may be disposed between the first encapsulationlayer 124 and the protecting layer 126 (as shown in FIG. 4 ). In someembodiments, the top surface of the retardation layer 140 may besubstantially level with the top surface of the second substrate 114.

It should be understood that although not all of the combinations ofdifferent types of display structures are illustrated in the figures,one with ordinary skill in the art can make suitable combinations ormodifications to the display device according to need. In addition,although the laser display structure is not specifically illustrated inthe figures, it has a structure that is substantially similar to thestructure of the inorganic light-emitting diode display. Therefore, thehybrid structures of the laser display and other types of displays willbe similar to those of the inorganic light-emitting diode and othertypes of displays.

Next, referring to FIGS. 5A-5E, FIGS. 5A-5E illustrate thecross-sectional views of the display device during the manufacturingprocess in accordance with some embodiments of the present disclosure.FIGS. 5A-5E illustrate some manufacturing processes of the displaydevice 10 in FIG. 1 as an example. Other display devices provided in thepresent disclosure may be formed by similar or corresponding processes,as shown in FIGS. 5A-5E. It should be understood that additionaloperations may be provided before, during, and after the processes ofthe manufacturing process in accordance with some embodiments. In someother embodiments, some of the operations described below may bereplaced or eliminated. In some embodiments, the order of the operationsmay be interchangeable.

First, as shown in FIG. 5A, the first substrate 102 is provided. Thefirst driving layer 108 is formed on the first side 102 a of the firstsubstrate 102. Next, referring to FIG. 5B, the sealing portion 128 isformed on the first side 102 a of the first substrate 102 and adjacentto the first driving layer 108. The sealing portion 128 can be incontact with the first driving layer 108. Then, referring to FIG. 5C,the second substrate 114′ on which the color filter layer 112 is formedis assembled with the first substrate 102 on which the first drivinglayer 108 is formed, and the liquid-crystal layer 110 is filled betweenthe first substrate 102 and the second substrate 114′.

Next, referring to FIG. 5D, a portion of the second substrate 114′ isremoved so that a portion of the sealing portion 128 is exposed.However, in some embodiments, the sealing portion 128 still includes aportion 128A that overlaps the second substrate 114. In other words, theportion 128A of the sealing portion 128 is disposed between the firstsubstrate 102 and the second substrate 114. Next, referring to FIG. 5E,the second driving layer 120, the first light-emitting layer 122, thefirst encapsulation layer 124 of the second display structure 106 areformed on the exposed region of the sealing portion 128, i.e. the regionthat is exposed by removal of the second substrate 114′. Then, theprotecting layer 126 is formed on the first encapsulation layer 124 andthe second substrate 114. In some embodiments, a planarization processcan be performed on the protecting layer 126 so that the protectinglayer has a substantially planarized top surface 126 a. Thereafter, thepolarizing structure 130 can be adhered to the protecting layer 126 bythe first adhesive layer 132.

Next, referring to FIGS. 6A-6C, FIGS. 6A-6C illustrate thecross-sectional views of a display device 50 in accordance with someembodiments of the present disclosure. As shown in FIG. 6A, the displaydevice 50 includes a first substrate 202, a first display structure 204and a second display structure 206. The first display structure 204 isdisposed on the first region R1 of the first substrate 202, and thesecond display structure 206 is disposed on the second region R2 of thefirst substrate 202. In some embodiments, the display device 50 may be awearable display device, in which the first display structure 204 canserve as a watch portion, and the second display structure 206 can serveas a belt portion. The structure of the display device 50 is simplifiedin FIG. 6A to 6C for clarity. The structure of the display device 50 issimilar to the structures of the above-mentioned display devices in FIG.1 to FIG. 4 , and the detailed descriptions are omitted herein. Forexample, in some embodiments, the first display device 204 is a liquidcrystal display or an organic light-emitting diode display, and thesecond display device 206 is an inorganic light-emitting diode displayor a laser display.

The first display structure 204 may be affixed on the first substrate202 through the adhesive layer 234. In addition, the display device 50may further include a controller 236 and a sensor 238 disposed on thefirst substrate 202. The controller 236 or the sensor 238 may bearranged adjacent to the second display structure 206. In someembodiments, the controller 236 may control and/or process the signalsgenerated from the second display structure 206 or the sensor 238. Insome embodiments, the sensor 238 may include, but is not limited to, alight sensing element, an infrared sensing element, a respirationsensing element, a heartbeat sensing element, a voice sensing element, afacial recognition element, a fingerprint sensing element, any othersuitable sensing elements, or a combination thereof.

The display device 50 may further include a protecting layer 226disposed on the second display structure 206. In some embodiments, theprotecting layer 226 may also be disposed on the first display structure204. The protecting layer 226 can be made of the materials suitable forforming the protecting layer 126 as mentioned above.

The display device 50 may further include a polarizing layer 230disposed on the first display structure 204 and the second displaystructure 206, and can be adhered to the protecting layer 226 and thefirst display structure 204 by an adhesive layer 232.

Next, referring to FIG. 6B, FIG. 6B illustrates the cross-sectional viewof the display device 50 in accordance with some other embodiments ofthe present disclosure. The difference between the embodiments shown inFIG. 6B and FIG. 6A is that the display device 50 further includes aretardation layer 240 disposed on the second display structure 206 inthe second region R2. The retardation layer 240 can be disposed betweenthe second display structure 206 and the first polarizing structure 230.In some embodiments, the retardation layer 240 can also extend to thefirst region R1 to be disposed on the first display structure 204, asshown in FIG. 6C.

Next, referring to FIG. 7A, FIG. 7A illustrates a cross-sectional viewof a display device 60 in accordance with some embodiments of thepresent disclosure. The display device 60 is similar as the displaydevice 10 shown in FIG. 1 , except that the display device 60 includestwo first display structures 104, and a second display structure 106 isdisposed between these two first display structures 104. In thisembodiment, the first substrate 102 can be a flexible substrate. In thisembodiment, a region 106A corresponding to the second display structure106 may serve as a foldable region. In this embodiment, the seconddisplay structure 106 may include an organic light-emitting diodedisplay, an inorganic light-emitting diode display, or a laser display,and the first display structure 104 may include a liquid-crystaldisplay.

Referring to FIG. 7B, FIG. 7B illustrates a diagram of the displaydevice 60 in a folded form. As shown in FIG. 7B, the region 106Acorresponding to the second display structure 106 is bent (or folded),while the regions 104A corresponding to the first display structure 104are not bent (or folded). However, it should be understood that althoughthe display device 60 of the embodiment shown in FIG. 7A includes twounfoldable regions (region 104A) and one foldable region (region 106A),other amounts or combinations of the foldable region and unfoldableregion may be applied according to the needs of some other embodiments.

Next, referring to FIG. 8A, FIG. 8A illustrates a cross-sectional viewof a display device 70 in accordance with some embodiments of thepresent disclosure. The difference between the display device 70 asshown in FIG. 8A and the display device 10 shown in FIG. 1 is that thedisplay device 70 further includes the retardation layer 140 and a lightreducing layer 142 disposed on the second display structure 106. Asshown in FIG. 8A, the light reducing layer 142 can be disposed betweenthe first encapsulation layer 124 and the retardation layer 140.Specifically, the light reducing layer 142 may be disposed on the regionwhere the second display structure 106 is disposed. In addition, thelight reducing layer 142 may be disposed at any position above thesecond display structure 106. For example, in some embodiments, thelight reducing layer 142 can be disposed between the retardation layer140 and the protecting layer 126, as shown in FIG. 8B. In someembodiments, the top surface of the retardation layer 140 may besubstantially level with the top surface of the second substrate 114,and thus the protecting layer 126 may be omitted.

The light reducing layer 142 may partially shield the light emitted fromthe second display structure 106 (e.g., the light emitted from the firstlight-emitting layer 122) and reduce the light intensity thereof. Sincethe light source of the first display structure 104 (i.e. the backlightunit 118) is more distant from the light emergent surface A than thelight source of the second display structure 106 (i.e. the firstlight-emitting layer 122), the light intensity of the images shown bythe first display structure 104 and the second display structure 106 maybe different. The light reducing layer 142 may reduce the lightintensity of the second display structure 106 so that the images shownby the first display structure 104 and the second display structure 106may be more consistent or uniform. In some embodiments, the lightreducing layer 142 may decrease the light intensity of the seconddisplay structure 106 with a level of about 50% to about 95%.

The light reducing layer 142 may be made of materials havinglight-shielding characteristics. In some embodiments, the materials ofthe light reducing layer 142 may include, but are not limited to,silicone and the particles formed of carbon, titanium (Ti), titaniumdioxides (TiO₂), quantum dot materials or a combination thereof. In someembodiments, the thickness of the light reducing layer 142 may be in arange from about 0.05 μm to about 10 μm. In some embodiments, the lightreducing layer 142 may be formed by using chemical vapor deposition(CVD), spin-on coating or printing.

The light intensity of the second display structure 106 (the firstlight-emitting layer 122) may also be decreased by current adjustmentthrough the second driving layer 120 or the panel driving portion 134 inaccordance with some embodiments. Furthermore, in some embodiments, thecolor filter layer 112 of the first display structure 104 may be formedof quantum dot materials to further increase the light intensity of thefirst display structure 104. Specifically, in some embodiments, thelight intensity of the backlight unit 118 and the light intensity of thesecond display structure 106 can be controlled, so as to obtain moreuniform light intensity at the light emergent surface A. For example,the ratio of the light intensity of the backlight unit 118 to the lightintensity of the second display structure 106 may be in a range fromabout 5 to about 30. The light intensity of the second display structure106 may be the light intensity measured at the light emergent surface Acorresponding to the region where the second display structure 106 islocated. In addition, the light intensity may be measured by aspectroradiometer, for example, by Konica Minolta (CS2000/CS2000A).

Next, referring to FIG. 9 , FIG. 9 illustrates a cross-sectional view ofa display device 80 in accordance with some embodiments of the presentdisclosure. The difference between the display device 80 shown in FIG. 9and the display device 40 shown in FIG. 1 is that the first polarizingstructure 930 includes two separate polarizing layers 931 and 932, and aretardation layer 140 is disposed on the second display structure 106.The polarizing layer 931 is disposed on the first display structure 104and adhered to the protecting layer 126 by an adhesive layer 951, andthe polarizing layer 932 is disposed on the second display structure 106and adhered to the protecting layer 126 by an adhesive layer 952. Inaddition, the top surface 932 a of the polarizing layer 932 may bealigned with the top surface 931 a of the polarizing layer 931 inaccordance with some embodiments. In other words, the top surface 931 aand the top surface 932 a may be substantially planarized.

Next, referring to FIG. 10 , FIG. 10 illustrates a cross-sectional viewof the display device 50 in accordance with some other embodiments ofthe present disclosure. The difference between the display device 50shown in FIG. 10 and FIG. 6A is that in the display device 50 in FIG. 10, the first polarizing structure 930 includes two separate polarizinglayers 931 and 932. The polarizing layer 931 is disposed on the firstdisplay structure 204 and adhered to the first display structure 204 byan adhesive layer 951, and the polarizing layer 932 is disposed on thesecond display structure 206 and adhered to the protecting layer 226 byan adhesive layer 952. In some embodiments, the first display structure204 can be a liquid-crystal display and can have a greater thicknessthan the second display structure 206. In such cases, it may havedifficult to adhere one polarizing layer on both the first displaystructure 204 and the second display structure 206 because of thedifference in thickness. In some embodiments, two separate polarizinglayers 931 and 932 can be adhered to the first display structure 204 andthe second display structure 206 respectively even if the thickness indifference exists.

Next, referring to FIG. 11 , FIG. 11 illustrates a cross-sectional viewof the display device 90 in accordance with some other embodiments ofthe present disclosure. The display device 90 is similar as the displaydevice 10 shown in FIG. 1 . The difference between the display device 90shown in FIG. 10 and the display device 10 shown in FIG. 1 is thestructure of the sealing portion. In some embodiments, a portion of thesealing portion can be removed, for example, by photolithography, toform an opening. Thus, the remained sealing portion 128 is defined asthe protruding portion 128P′ and the portion corresponding to theopening, which is defined as the recess portion 128R′. From a top viewperspective, the protruding portion 128P′ can be disposed between thefirst display structure 104 and the second display structure 106. From across-sectional view perspective, the second display structure 106 isdisposed on the recess portion 128R′. The protruding portion 128P′protrudes from the first side 102 a of the first substrate 102 towardthe second side 114 b of the second substrate 114, and can be disposedbetween the first substrate 102 and the second substrate 114. In someembodiments, the protruding portion 128P′ of the sealing portion 128 isdisposed between the first light-emitting layer 122 of the seconddisplay structure 106 and the liquid-crystal layer 108 of the firstdisplay structure 104. The recess portion 128R′ of the sealing portion128 may have a fifth thickness T₅, and the protruding portion 128P′ ofthe sealing portion 128 may have a sixth thickness T₆. In someembodiments, the fifth thickness T₅ is smaller than the sixth thicknessT₆.

Next, referring to FIG. 12 , FIG. 12 illustrates a cross-sectional viewof the display device 200 in accordance with some other embodiments ofthe present disclosure. The difference between the display device 200shown in FIG. 12 and the display device 10 shown in FIG. 1 is that thesecond substrate 114′ includes an extending portion 114E′. In someembodiments, a portion of the second substrate 114′ can be removed, forexample, by photolithography, to form an opening. The portioncorresponding to the opening is defined as extending portion 114E′. Theextending portion 114E′ extends from the first display structure 104 tothe second display structure 106. The extending portion 114E′ isdisposed between the sealing portion 128 and the second displaystructure 106. Specifically, the second driving layer 120, the firstlight-emitting layer 122 and first encapsulation layer 124 are disposedon the extending portion 114E′. In such a configuration, the secondsubstrate 114′ may be connected to other adjacent components in aseamless way. Moreover, the extending portion 114E′ of the secondsubstrate 114′ may have a seventh thickness T₇, and the second substrate114′ may have an eighth thickness T₈. In some embodiments, the sevenththickness T₇ is smaller than the eighth thickness T₈.

Next, referring to FIG. 13 , FIG. 13 illustrates a cross-sectional viewof the display device 300 in accordance with some embodiments of thepresent disclosure. As shown in FIG. 13 , the first driving layer 108and the second driving layer 120 may be electrically connected to thepanel driving portion 134 by a via 152A and a via 152B in accordancewith some embodiments. The via 152A and the via 152B may be formed ofconductive materials. The conductive material can include, but is notlimited to, copper, aluminum, tungsten, titanium, gold, platinum,nickel, copper alloys, aluminum alloys, tungsten alloys, titaniumalloys, gold alloys, platinum alloys, nickel alloys, any other suitableconductive materials, or a combination thereof. In some embodiments, anopening may be formed in the first substrate 102, and the aboveconductive material can be filled in the opening to form the via 152A.An opening can be formed in the sealing portion 128 and the firstsubstrate 102, and the above conductive material can be filled in theopening to form the via 152B.

Next, referring to FIG. 14A, FIG. 14A illustrates a cross-sectional viewof the display device 400 in accordance with some embodiments of thepresent disclosure. The difference between the display device 400 shownin FIG. 14A and the display device 10 shown in FIG. 1 is that thedesigns of the display structures and backlight sources are different.As shown in FIG. 14A, a wire-grid polarizer 154 and a first wavelengthconversion layer 41Q are disposed in the first display structure 104.For example, the wire-grid polarizer 154 and the first wavelengthconversion layer 41Q are disposed on the second substrate 114, and thenthe second substrate 114 and the first substrate 102 can be assembled toform the first display structure 104. The first wavelength conversionlayer 41Q can be disposed between the wire-grid polarizer 154 and thesecond substrate 114. In the second display structure 106, the firstlight-emitting layer 122A can include light emitting diodes of a singlecolor (for example, blue light emitting diodes), and a second wavelengthconversion layer 42Q is disposed on the first light-emitting layer 122A.In some embodiments, the backlight unit 118 and the first light-emittinglayer 122A may emit the light with a wavelength of about 350 nm to about450 nm. For example, the backlight unit 118 and the first light-emittinglayer 122A may emit UV light in accordance with some embodiments. Insome embodiments, the backlight unit 118 and the first light-emittinglayer 122A may emit the light of blue color.

The wire-grid polarizer 154 may be formed of metallic materials. In someembodiments, the metallic materials may include, but are not limited to,copper, aluminum, tungsten, titanium, gold, platinum, nickel, cobalt,chrome, silver, copper alloys, aluminum alloys, tungsten alloys,titanium alloys, gold alloys, platinum alloys, nickel alloys, cobaltalloys, chrome alloys, silver alloys, any other suitable conductivematerials, or a combination thereof.

In this embodiment, the first wavelength conversion layer 41Q and thesecond wavelength conversion layer 42Q may be formed of quantum dotmaterials. The quantum dot material may have a core-shell structure. Thecore structure may include, but is not limited to, CdSe, CdTe, CdS, ZnS,ZnSe, ZnO, ZnTe, InAs, InP, GaP, or any other suitable materials, or acombination thereof. The shell structure may include, but is not limitedto, ZnS, ZnSe, GaN, GaP, or any other suitable materials, or acombination thereof. In addition, as described above, the backlight unit118 may emit UV light and the quantum dot material of the firstwavelength conversion layer 41Q may be excited to generate red light,green light or blue light in accordance with some embodiments.Similarly, the first light-emitting layer 122A may emit UV light and thequantum dot material of the second wavelength conversion layer 42Q maybe excited to generate red light, green light or blue light inaccordance with some embodiments.

Next, referring to FIG. 14B, FIG. 14B illustrates a cross-sectional viewof the display device 400 in accordance with some other embodiments ofthe present disclosure. The display device 400 shown in FIG. 14B issimilar as that shown in FIG. 14A. FIG. 14B differs from FIG. 14A inthat the first wavelength conversion layer 45Q and the second wavelengthconversion layer 46Q do not include the material for converting bluelight. The backlight unit 118 and the first light-emitting layer 122Acan emit blue light, for example, emit the light with a wavelength ofabout 450 nm to about 495 nm. Thus, the light output of the backlightunit 118 and the first light-emitting layer 122A can also include red,green, and blue lights.

Next, referring to FIG. 15 , FIG. 15 illustrates a diagram showing thepixels of the display units in a display device 600 in accordance withsome embodiments of the present disclosure. The display device 600 mayinclude two display units, a first display unit 100A and a seconddisplay unit 100B, connected to each other. For example, the displayunit 100A and the display unit 100B may be connected by mechanicalelements (not shown). Specifically, the second display unit 100B isconnected to the first display unit 100A along a first direction (Xdirection) in a side-by-side manner. In some embodiments, the displaydevice 600 may be a tiled (mosaic) display device including more thanone display units. The display unit 100A and the display unit 100B mayhave similar structures as any display device described above. Forexample, the first display unit 100A may include a first substrate 601,a first display structure 104, and a second display structure 106. Thefirst display structure 104 can be disposed on a first region R1 of thefirst substrate 601, and the second display structure 106 can bedisposed on a second region R2 of the first substrate 601. In addition,the second display unit 100B may include a third substrate 603, a thirddisplay structure 306, and a fourth display structure 304. The thirddisplay structure 306 can be disposed on a third region R3 of the thirdsubstrate 603, and the fourth display structure 304 can be disposed on afourth region R4 of the third substrate 603. In some embodiments, thesecond display structure 106 and the third display structure 306 can beformed of the same type of display. For example, both of the seconddisplay structure 106 and the third display structure 306 can be organiclight-emitting diode displays, inorganic light-emitting diode displays,or laser displays.

The first display structure 104 and the second display structure 106 mayinclude a plurality of first pixels 612 and a plurality of second pixels622 respectively. Similarly, the third display structure 306 and thefourth display structure 304 may include a plurality of third pixels 322and a plurality of fourth pixels 312 respectively.

In addition, each of the first pixel 612 may include first subpixels 612a, 612 b and 612 c. Each of the second pixel 622 may include secondsubpixels 622 a, 622 b and 622 c. In some embodiments, the first pixels612 have a first pitch p₁. The first pitch p₁ may be defined as adistance between a first subpixel 612 a and the next (the closest) firstsubpixel 612 a, or a distance between a first subpixel 612 b and thenext (the closest) first subpixel 612 b, or a distance between a firstsubpixel 612 c and the next (the closest) first subpixel 612 c. In onefirst pixel 612, the three subpixel 612 a, 612 b, and 612 c can emitlights of different colors. In one second pixel 622, the three subpixel622 a, 622 b, and 622 c can emit lights of different colors. In someembodiments, the two adjacent first pixel and second pixel define asecond pitch p₂. Specifically, as shown in FIG. 15 , the first pixel 61p of the first display structure 104 and the second pixel 62 p of thesecond display structure 106 are adjacent to each other, and thedistance between the first pixel 61 p and the second pixel 62 p definesthe second pitch p₂. In some embodiments, a ratio of the first pitch p₁to the second pitch p₂ ranges from 0.8 to 1.2. In such an arrangement,the images difference between the first display structure 104 and thesecond display structure 106 may be reduced.

In addition, each of the third pixel 322 may include third subpixels 322a, 322 b and 322 c, which can emit lights of different colors. Each ofthe fourth pixel 312 may include fourth subpixels 312 a, 312 b and 312c, which can emit lights of different colors. In some embodiments, thetwo adjacent second pixel and third pixel define a third pitch p₃.Specifically, as shown in FIG. 15 , the second pixel 62 x of the seconddisplay structure 106 and the third pixel 63 x of the third displaystructure 306 are adjacent to each other, and the distance between thesecond pixel 62 x and the third pixel 63 x defines the third pitch p₃.In some embodiments, a ratio of the first pitch p₁ to the third pitch p₃ranges from 0.8 to 1.2. In such an arrangement, the images differencebetween the display unit 100A and display unit 100B may be reduced.

In addition, as shown in FIG. 15 , in the second display structure 106,the two adjacent second pixels 622 are spaced apart from each other by afirst distance d₁ in accordance with some embodiments. Specifically,referring to the two adjacent second pixel 622-1 and second pixel 622-2,the third subpixel 622 c in the pixel 622-1 and the first subpixel 622 ain the pixel 622-2 are spaced apart from each other by the firstdistance d₁. In some embodiments, the first distance d₁ may also bedefined as the closest distance between two second pixels 622.

Moreover, in some embodiments, by using the mechanical elements (notshown) for connection, the first substrate 601 of the first display unit100A and the third substrate 603 of the second display unit 100B can bedesigned to be very close to each other. In other words, the side S1 ofthe first substrate 601 and the side S2 of the third substrate 603 canbe very close to each other. In some embodiments, a distance between thesecond subpixel of the second display structure 106 nearest to the firstconnecting side S1 of the first substrate 601 defines a second distanced₂. Specifically, a distance between the second subpixel 622 c of thesecond pixel 62 x nearest to the first connecting side S1 defines thesecond distance d₂. In addition, a distance between the third subpixelof the third display structure 306 nearest to the second connecting sideS2 of the third substrate 603 defines a third distance d₃. Specifically,a distance between the third subpixel 322 a of the third pixel 63 xnearest to the second connecting side S2 of the third substrate 603defines the third distance d₃. In some embodiments, a ratio of the firstdistance d₁ to the sum of the second distance d₂ and the third distanced₃ ranges from 0.8 to 1.2. In such an arrangement, the images differencebetween the display unit 100A and display unit 100B may be reduced.

Next, referring to FIG. 16 , FIG. 16 illustrates a diagram showing theassembly of the display units 700U in accordance with some embodimentsof the present disclosure. As shown in FIG. 16 , the display unit 700Umay have similar structure as the display device 70 shown in FIG. 8A.However, it should be understood that although the display unit 700U hasa similar structure as the display device 70 shown in FIG. 8A, thedisplay unit 700U may have similar structures as any display devicedescribed above in some other embodiments. The difference between thedisplay device 70 as shown in FIG. 8A and the display unit 700U shown inFIG. 16 is that the display unit 700U further includes a flexible regionF disposed at an end of the display unit 700U. Specifically, theflexible region F includes a first flexible portion 102F at an end ofthe first substrate 102 and a second flexible portion 128F at an end ofthe sealing portion 128. The sealing portion 128 may protrude from thesidewall of the second display structure 106 and form the secondflexible portion 128F. The first substrate 102 may also protrude fromthe sidewall of the second display structure 106 and form the firstflexible portion 102F. In some embodiments, an area of the firstflexible portion 102F is greater than an area of the second flexibleportion 128F. In other words, the first substrate 102 may protrudefarther away from the sidewall of the second display structure 106 thanthe sealing portion 128 protrudes, so that a step-like structure may beformed. In some embodiments, a signal circuit 158 may be disposed alongthe step-like structure of the first flexible portion 102F and thesecond flexible portion 128F and provide an electrical connectionbetween the second driving layer 120 and the panel driving portion 134.In some embodiments, the electronic circuit 158 may include, but is notlimited to, an integrated circuit (IC), a microchip, any other suitableelectronic elements, or a combination thereof.

As shown in FIG. 16 , the flexible region F may be bent downwardly to beon the second side 102 b (backside) of the first substrate 102 to form afolded structure. In some embodiments, at least two display units 700Ucan be connected to each other to form a display device 700. Since aportion of the sealing portion 128 and a portion of the first substrate102 are folded downwardly to the backside, the display units 700U can beassembled together in a closer manner. With such a configuration, thedisplay units 700 may be connected even in a seamless way.

To summarize the above, the display device provided in the presentdisclosure includes different display structures disposed on the samesubstrate. A polarizing structure is disposed on the different types ofdisplay structures, so that heterogeneity between the images generatedby different types of display structures may be reduced. The quality anduniformity of the image that are displayed may be improved accordingly.In addition, in accordance with some embodiments of the presentdisclosure, the display device can be a tiled display device including afirst display unit and a second display unit. In accordance with someembodiments of the present disclosure, the pixel pitch and the distancebetween pixels are arranged in a specific manner so that the imagedifference at the boundary of the tiled display device may be reduced.

Although some embodiments of the present disclosure and their advantageshave been described in detail, it should be understood that variouschanges, substitutions and alterations can be made herein withoutdeparting from the spirit and scope of the disclosure as defined by theappended claims. For example, it will be readily understood by one ofordinary skill in the art that many of the features, functions,processes, and materials described herein may be varied while remainingwithin the scope of the present disclosure. Moreover, the scope of thepresent application is not intended to be limited to the particularembodiments of the process, machine, manufacture, composition of matter,means, methods and steps described in the specification. As one ofordinary skill in the art will readily appreciate from the presentdisclosure, processes, machines, manufacture, compositions of matter,means, methods, or steps, presently existing or later to be developed,that perform substantially the same function or achieve substantiallythe same result as the corresponding embodiments described herein may beutilized according to the present disclosure. Accordingly, the appendedclaims are intended to include within their scope such processes,machines, manufacture, compositions of matter, means, methods, or steps.

What is claimed is:
 1. A display device, comprising: a first substrate; a first display structure disposed on the first substrate; a second display structure disposed on the first substrate; a first optical film and a second optical film, wherein the first display structure is disposed between the first substrate and the first optical film, the second display structure is disposed between the first substrate and the second optical film, and the first optical film and the second optical film are separated; and a first adhesive layer and a second adhesive layer, wherein the first adhesive layer is disposed between the first display structure and first optical film, the second adhesive layer is disposed between the second display structure and second optical film, wherein the first display structure and the second display structure are different from each other and are selected from a group consisting of: a liquid-crystal display; an organic light-emitting diode display; an inorganic light-emitting diode display; and a laser display.
 2. The display device as claimed in claim 1, further comprising a driving portion electrically connected to the first display structure and the second display structure.
 3. The display device as claimed in claim 1, wherein the first display structure and the second display structure are non-coplanar.
 4. The display device as claimed in claim 1, wherein the first display structure is a liquid-crystal display and the second display structure is an organic light-emitting diode display.
 5. The display device as claimed in claim 4, wherein the first display structure further comprises a backlight unit.
 6. The display device as claimed in claim 4, wherein the first display structure further comprises: a second substrate disposed on the first substrate; and a liquid-crystal layer disposed between the first substrate and the second substrate; wherein the display device further comprises a sealing portion disposed adjacent to the liquid-crystal layer; and wherein the sealing portion at least partially overlaps the second substrate.
 7. The display device as claimed in claim 6, further comprising a driving portion electrically connected to the first display structure.
 8. The display device as claimed in claim 4, further comprising a retardation layer disposed on the second display structure.
 9. The display device as claimed in claim 1, wherein the first optical film does not overlap with the second optical film.
 10. The display device as claimed in claim 1, wherein a thickness of the first optical film is different from a thickness of the second optical film.
 11. The display device as claimed in claim 1, wherein the first adhesive layer and the second adhesive layer are separated.
 12. The display device as claimed in claim 1, wherein at least one of the first optical film and the second optical film is a polarizer.
 13. The display device as claimed in claim 1, wherein at least one of the first optical film and the second optical film is an anti-reflective layer.
 14. The display device as claimed in claim 1, wherein the first display structure is a liquid-crystal display, and the first optical film is a polarizer.
 15. The display device as claimed in claim 1, wherein a lower surface of the first optical film and a lower surface of the second optical film are non-coplanar.
 16. The display device as claimed in claim 1, wherein the first adhesive layer and the second adhesive layer are non-coplanar.
 17. The display device as claimed in claim 1, wherein a resolution of the first display structure is different from a resolution of the second display structure.
 18. The display device as claimed in claim 1, further comprising a protecting layer disposed on the second display structure.
 19. The display device as claimed in claim 18, further comprising a retardation layer disposed on the protecting layer.
 20. The display device as claimed in claim 1, wherein a top surface of the first optical film and a top surface the second optical film are non-coplanar. 